Subcellular Quantitative Determination of K and Ca in Phloem, Cambium, and Xylem Cells of Spruce(Picea abies[L.] Karst.) During Earlywood and Latewood Formation

Abstract

The present investigation was directed to calibrated subcellular quantitative determination of K and Ca in phloem, cambium, and xylem cells of spruce (Picea abies [L] Karst.) by energy dispersive X-ray spectroscopy (EDXS) in combination with transmission electron microscopy (TEM). The element content was studied during earlywood and latewood formation throughout primary and secondary wall formation and lignification. In the experimental stage, increment cores were extracted from three 100-year-old forest trees and either shock-frozen, embedded, and used for semithin cuttings, or prepared for optical emission spectroscopy (ICP-OES) for bulk analysis from tissue sections. The structural dynamics in cell formation of phloem, cambium, and xylem was expressed in terms of the radial cell diameter and the cell wall area. The lignification of the same cells was studied by subcellular UV-spectroscopy. During earlywood formation, differentiating tracheids are a strong physiological sink for K. Particularly during cell enlargement, a strong increase of the symplasmatic K content (> 1 ng per cell) was detected. An increase of the Ca content of differentiating cells (0.4-1 ng per cell) was found during secondary wall formation, whereas the Ca content of the cell wall decreased remarkably during its lignification (0.1-0.3 ng per cell). From these experiments it can be concluded that K is a driving force in cell enlargement of differentiating tracheids (primary wall phase), whereas Ca is of importance especially for wall synthesis in the secondary phase of xylem cell development and lignification.

A systems biology view of wood formation in Eucalyptus grandis trees submitted to different potassium and water regimes

“…K also influences xylem structure, probably through its role in turgor‐driven elongation of new xylem cells. It has an impact on the deposition dynamics of SCWs as K‐starved trees show earlier initiation of SCW deposition than controls (Dunisch et al ., ; Langer et al ., ).…”

Sclerophylly in Qualea Parviflora (Vochysiaceae): Influence of Herbivory, Mineral Nutrients, and Water Status

“…Arens (1958a, b) attributed the scleromorphic traits of cerrado plant species to the mineral deficiency, particularly N, P, Ca and S, which would limit plant growth, provide accumulation of carbohydrates, and deposit in the wall of plant cell, as cellulose, sclerenchyma and other mechanical structures. Also, some authors (Eklund and Eliasson 1990;Dunisch et al 1998) found that the reduction of the thickness of the cellular wall in some plants is influenced by potassium, which in high concentration decrease calcium absorption. These authors observed an increased of synthesis of cellular wall, and higher lignification with increasing concentration of calcium.…”

Polar-localised poplar K+ channel capable of controlling electrical properties of wood-forming cells

“…These studies revealed that potassium homeostasis in trees depends on the availability of mineral nutrients, the state of mycorrhizal association as well as the physiological condition of the plant. During cambial growth K + ions have been shown to be involved in various aspects of xylogenesis (Du¨nisch and Bauch 1994a, b;Kuhn et al 1997), such as cell expansion via increase of the symplastic K + content (Du¨nisch et al 1998) and xylem differentiation . Furthermore K + fertilisation resulted in a 30% increased biomass and enlarged annual rings as a result of the potassium peak in the cambial region during the active growth period of trees (Kuhn et al 1997;Arend et al 2002).…”